#include<iostream>
using namespace std;
class A
{
public:
    void Show()
    {
        cout << "A::Show()" << endl;
    }
public:
    int ma = 10;
};
class B : public A
{
public:
    void Show()
    {
        cout << "B::Show" << endl;
    }
public:
    int ma = 20;
};

int main()
{
   A *pa = NULL;
    B *pb = NULL;
    B b;
    pa = &b;
    pa->Show();
    pb = &b;
    pb->Show();
    return 0;
}

